EARTH Western Europe -- 10 Apr 2015 -- This NASA MODIS satellite image from 10 Apr 2015 (latest available from the Terra sensor) showing a build up of air pollution over south-eastern England

EARTH Western Europe -- 10 Apr 2015 -- This NASA MODIS satellite image from 10 Apr 2015 (latest available from the Terra sensor) showing a build up of air pollution over south-eastern England and other parts of Europe (the grey-coloured clouds). Parts of the UK could reach the highest level of air pollution on Friday, prompting health warnings. Warm, still conditions are expected to combine with traffic fumes, pollution from the continent and Saharan dust from the south as it rises to level 10 (the highest level). Much of the south east and eastern England will see high levels of pollution, although the problem is expected to be short-lived and disapate by Saturday, according to DEFRA -- Picture by Atlas Photo Archive/NASA